#!/bin/sh

# run from directory where this script is
cd `echo $0 | sed 's/\(.*\)\/.*/\1/'` # extract pathname
EXAMPLE_DIR=`pwd`

# Path for Wannier90
WAN_DIR=../../../wannier90-1.2

# check whether echo has the -e option
if test "`echo -e`" = "-e" ; then ECHO=echo ; else ECHO="echo -e" ; fi

$ECHO
$ECHO "$EXAMPLE_DIR : starting"
$ECHO
$ECHO "This example shows how to use pw2wannier90.x in conjunction with" 
$ECHO "Wannier90 (http://www.wannier.org) to obtain maximally-localised"
$ECHO "Wannier functions (MLWFs) for the valence bands of diamond."
$ECHO "Wannier90 may be run in two modes, 'library' and 'standalone',"
$ECHO "and both of these are demonstrated."
$ECHO "for library mode pw2wannier90 has to be compile with -D__WANLIB flag,"
$ECHO "libwannier.a has to be linked. Uncomment related lines below."

# set the needed environment variables 
. ../../../environment_variables

# required executables and pseudopotentials
BIN_LIST="pw.x pw2wannier90.x"
PSEUDO_LIST="C.pz-vbc.UPF"

$ECHO
$ECHO "  executables directory: $BIN_DIR"
$ECHO "  pseudo directory:      $PSEUDO_DIR"
$ECHO "  temporary directory:   $TMP_DIR"
$ECHO "  checking that needed directories and files exist...\c"

# check for directories
for DIR in "$BIN_DIR" "$PSEUDO_DIR" ; do
    if test ! -d $DIR ; then 
        $ECHO
        $ECHO "ERROR: $DIR not existent or not a directory"
        $ECHO "Aborting"
        exit 1
    fi
done
for DIR in "$TMP_DIR" "$EXAMPLE_DIR/results" ; do
    if test ! -d $DIR ; then
        mkdir $DIR
    fi
done
cd $EXAMPLE_DIR/results

# check for executables
for FILE in $BIN_LIST ; do
    if test ! -x $BIN_DIR/$FILE ; then
        $ECHO
        $ECHO "ERROR: $BIN_DIR/$FILE not existent or not executable"
        $ECHO "Aborting"
        exit 1
    fi
done

# check for wannier90 executable
if test ! -x "$BIN_DIR/wannier90.x" ; then
    $ECHO 
    $ECHO "ERROR: '$BIN_DIR/wannier90.x' not existent or not executable"
    $ECHO "Aborting"
    exit 1
fi

# check for pseudopotentials
for FILE in $PSEUDO_LIST ; do
    if test ! -r $PSEUDO_DIR/$FILE ; then
       $ECHO
       $ECHO "Downloading $FILE to $PSEUDO_DIR...\c"
            $WGET $PSEUDO_DIR/$FILE $NETWORK_PSEUDO/$FILE 2> /dev/null
    fi
    if test $? != 0; then
        $ECHO
        $ECHO "ERROR: $PSEUDO_DIR/$FILE not existent or not readable"
        $ECHO "Aborting"
        exit 1
    fi
done
$ECHO " done"

# how to run executables
PW_COMMAND="$PARA_PREFIX $BIN_DIR/pw.x $PARA_POSTFIX"
WAN_COMMAND="$BIN_DIR/wannier90.x"
PW2WAN_COMMAND="$PARA_PREFIX $BIN_DIR/pw2wannier90.x $PARA_POSTFIX"
$ECHO
$ECHO "  running pw.x as          : $PW_COMMAND"
$ECHO "  running wannier90.x as   : $WAN_COMMAND"
$ECHO "  running pw2wannier90.x as: $PW2WAN_COMMAND"
$ECHO

# self-consistent calculation for diamond
cat > diamond.scf.in << EOF
 &control
    calculation = 'scf'
    restart_mode='from_scratch',
    prefix='di',
    pseudo_dir='$PSEUDO_DIR',
    outdir='$TMP_DIR'
 /
 &system    
    ibrav=  2, celldm(1) =6.1, nat=  2, ntyp= 1,
    ecutwfc =40.0, 
 /
 &electrons
    diagonalization='david'
    mixing_mode = 'plain'
    mixing_beta = 0.7 
    conv_thr =  1.0d-13
 /
ATOMIC_SPECIES
 C  12.0  C.pz-vbc.UPF
ATOMIC_POSITIONS {crystal}
C  -0.25 -0.25 -0.25
C   0.0  0.0  0.0
K_POINTS {automatic}
 12 12 12 0 0 0
EOF
$ECHO "  running the scf calculation for diamond...\c"
$PW_COMMAND < diamond.scf.in > diamond.scf.out
$ECHO " done"

# non-self-consistent calculation for diamond
cat > diamond.nscf.in << EOF
 &control
    calculation='nscf'
    pseudo_dir='$PSEUDO_DIR',
    outdir='$TMP_DIR',
    prefix='di'
 /
 &system    
    ibrav=  2, celldm(1) =6.1, nat=  2, ntyp= 1,
    ecutwfc =40.0, nbnd = 4,
 /
 &electrons
    conv_thr =  1.0d-11
 /
ATOMIC_SPECIES
 C  12.0  C.pz-vbc.UPF
ATOMIC_POSITIONS {crystal}
C -0.25 -0.25 -0.25
C  0.0  0.0  0.0
K_POINTS {crystal}
 64 
0.0000  0.0000   0.0000   0.0156250
0.0000  0.2500   0.0000   0.0156250
0.0000  0.5000   0.0000   0.0156250
0.0000  0.7500   0.0000   0.0156250
0.2500  0.0000   0.0000   0.0156250
0.2500  0.2500   0.0000   0.0156250
0.2500  0.5000   0.0000   0.0156250
0.2500  0.7500   0.0000   0.0156250
0.5000  0.0000   0.0000   0.0156250
0.5000  0.2500   0.0000   0.0156250
0.5000  0.5000   0.0000   0.0156250
0.5000  0.7500   0.0000   0.0156250
0.7500  0.0000   0.0000   0.0156250
0.7500  0.2500   0.0000   0.0156250
0.7500  0.5000   0.0000   0.0156250
0.7500  0.7500   0.0000   0.0156250
0.0000  0.0000   0.2500   0.0156250
0.0000  0.2500   0.2500   0.0156250
0.0000  0.5000   0.2500   0.0156250
0.0000  0.7500   0.2500   0.0156250
0.2500  0.0000   0.2500   0.0156250
0.2500  0.2500   0.2500   0.0156250
0.2500  0.5000   0.2500   0.0156250
0.2500  0.7500   0.2500   0.0156250
0.5000  0.0000   0.2500   0.0156250
0.5000  0.2500   0.2500   0.0156250
0.5000  0.5000   0.2500   0.0156250
0.5000  0.7500   0.2500   0.0156250
0.7500  0.0000   0.2500   0.0156250
0.7500  0.2500   0.2500   0.0156250
0.7500  0.5000   0.2500   0.0156250
0.7500  0.7500   0.2500   0.0156250
0.0000  0.0000   0.5000   0.0156250
0.0000  0.2500   0.5000   0.0156250
0.0000  0.5000   0.5000   0.0156250
0.0000  0.7500   0.5000   0.0156250
0.2500  0.0000   0.5000   0.0156250
0.2500  0.2500   0.5000   0.0156250
0.2500  0.5000   0.5000   0.0156250
0.2500  0.7500   0.5000   0.0156250
0.5000  0.0000   0.5000   0.0156250
0.5000  0.2500   0.5000   0.0156250
0.5000  0.5000   0.5000   0.0156250
0.5000  0.7500   0.5000   0.0156250
0.7500  0.0000   0.5000   0.0156250
0.7500  0.2500   0.5000   0.0156250
0.7500  0.5000   0.5000   0.0156250
0.7500  0.7500   0.5000   0.0156250
0.0000  0.0000   0.7500   0.0156250
0.0000  0.2500   0.7500   0.0156250
0.0000  0.5000   0.7500   0.0156250
0.0000  0.7500   0.7500   0.0156250
0.2500  0.0000   0.7500   0.0156250
0.2500  0.2500   0.7500   0.0156250
0.2500  0.5000   0.7500   0.0156250
0.2500  0.7500   0.7500   0.0156250
0.5000  0.0000   0.7500   0.0156250
0.5000  0.2500   0.7500   0.0156250
0.5000  0.5000   0.7500   0.0156250
0.5000  0.7500   0.7500   0.0156250
0.7500  0.0000   0.7500   0.0156250
0.7500  0.2500   0.7500   0.0156250
0.7500  0.5000   0.7500   0.0156250
0.7500  0.7500   0.7500   0.0156250
EOF
$ECHO "  running the nscf calculation for diamond...\c"
$PW_COMMAND < diamond.nscf.in > diamond.nscf.out
$ECHO " done"

# Wannier90 to get nnkp
cat > diamond.win << EOF
num_wann        =  4 
num_iter        = 20

begin atoms_frac
C   -0.2500  -0.250    -0.25000
C    0.00000   0.0000     0.000000
end atoms_frac

begin projections
f=0.0,0.0,0.0:s
f=0.0,0.0,0.5:s
f=0.0,0.5,0.0:s
f=0.5,0.0,0.0:s
end projections

#begin unit_cell_cart
#-1.613990   0.000000   1.613990
# 0.000000   1.613990   1.613990
#-1.613990   1.613990   0.000000
#end unit_cell_cart

begin unit_cell_cart
bohr
-3.050   0.000   3.050
 0.000   3.050   3.050
-3.050   3.050   0.000 
end_unit_cell_cart

mp_grid : 4 4 4

begin kpoints
0.0000  0.0000   0.0000
0.0000  0.2500   0.0000
0.0000  0.5000   0.0000
0.0000  0.7500   0.0000
0.2500  0.0000   0.0000
0.2500  0.2500   0.0000
0.2500  0.5000   0.0000
0.2500  0.7500   0.0000
0.5000  0.0000   0.0000
0.5000  0.2500   0.0000
0.5000  0.5000   0.0000
0.5000  0.7500   0.0000
0.7500  0.0000   0.0000
0.7500  0.2500   0.0000
0.7500  0.5000   0.0000
0.7500  0.7500   0.0000
0.0000  0.0000   0.2500
0.0000  0.2500   0.2500
0.0000  0.5000   0.2500
0.0000  0.7500   0.2500
0.2500  0.0000   0.2500
0.2500  0.2500   0.2500
0.2500  0.5000   0.2500
0.2500  0.7500   0.2500
0.5000  0.0000   0.2500
0.5000  0.2500   0.2500
0.5000  0.5000   0.2500
0.5000  0.7500   0.2500
0.7500  0.0000   0.2500
0.7500  0.2500   0.2500
0.7500  0.5000   0.2500
0.7500  0.7500   0.2500
0.0000  0.0000   0.5000
0.0000  0.2500   0.5000
0.0000  0.5000   0.5000
0.0000  0.7500   0.5000
0.2500  0.0000   0.5000
0.2500  0.2500   0.5000
0.2500  0.5000   0.5000
0.2500  0.7500   0.5000
0.5000  0.0000   0.5000
0.5000  0.2500   0.5000
0.5000  0.5000   0.5000
0.5000  0.7500   0.5000
0.7500  0.0000   0.5000
0.7500  0.2500   0.5000
0.7500  0.5000   0.5000
0.7500  0.7500   0.5000
0.0000  0.0000   0.7500
0.0000  0.2500   0.7500
0.0000  0.5000   0.7500
0.0000  0.7500   0.7500
0.2500  0.0000   0.7500
0.2500  0.2500   0.7500
0.2500  0.5000   0.7500
0.2500  0.7500   0.7500
0.5000  0.0000   0.7500
0.5000  0.2500   0.7500
0.5000  0.5000   0.7500
0.5000  0.7500   0.7500
0.7500  0.0000   0.7500
0.7500  0.2500   0.7500
0.7500  0.5000   0.7500
0.7500  0.7500   0.7500
end kpoints
EOF

# STANDALONE MODE
$ECHO
$ECHO "  <== Stand-alone Mode ==>\c"
$ECHO

mv diamond.win diamond.sa.win

# run wannier90 to get nnkp file
$ECHO "  running wannier90 -pp for diamond...\c"
$WAN_COMMAND -pp diamond.sa
$ECHO " done"

# run pw2wannier90 to get overlap matrices
cat > diamond.pw2wan.sa.in << EOF
&inputpp 
   outdir = '$TMP_DIR/'
   prefix = 'di'
   seedname = 'diamond.sa'
   spin_component = 'none'
   write_mmn = .true.
   write_amn = .true.
   write_unk = .false.
   wan_mode = 'standalone'
/
EOF
$ECHO "  running pw2wannier90 in stand-alone mode for diamond...\c"
$PW2WAN_COMMAND < diamond.pw2wan.sa.in > diamond.pw2wan.sa.out
$ECHO " done"

# clean TMP_DIR
#$ECHO "  cleaning $TMP_DIR...\c"
#rm -rf $TMP_DIR/pwscf*
#$ECHO " done"

# run Wannier90 to obtain MLWFs
$ECHO "  running wannier90 for diamond...\c"
$WAN_COMMAND diamond.sa
$ECHO " done"

#########################################################
# LIBRARY MODE
########################################################
#$ECHO
#$ECHO "  <== Library Mode ==> \c"
#$ECHO

cp diamond.sa.win diamond.lib.win

# run pw2wannier90 to get overlap matrices
cat > diamond.pw2wan.lib.in << EOF
&inputpp 
   outdir = '$TMP_DIR/'
   prefix = 'di'
   seedname = 'diamond.lib'
   spin_component = 'none'
   write_mmn = .true.
   write_amn = .true.
   write_unk = .false.
   wan_mode = 'library'
/
EOF
#$ECHO "  running pw2wannier90 in library mode for diamond...\c"
#$PW2WAN_COMMAND < diamond.pw2wan.lib.in > diamond.pw2wan.lib.out
#$ECHO " done"

############################################################

#clean TMP_DIR
$ECHO
$ECHO "  cleaning $TMP_DIR...\c"
rm -rf $TMP_DIR/di.*
$ECHO
$ECHO "$EXAMPLE_DIR : done"
$ECHO
